The TPGs have it tough in that they have to spot all these things as well as look at authenticity, hidden problems and overall grade. The job can be very difficult for the TPGs. In this sense, CAC has it a bit easier for some coins since, for example, a previously puttied gold might have had the putty dry and "turn", which then allows CAC to spot the putty with relative ease. Some folks might state that CAC is better because they spotted the putty, for example, but there is no assurance that they would have spotted it if they had seen the coin upon submission to the TPG. I cannot speak for what the TPGs and CAC will accept as a manipulation other than the TPGs definitely will accept a properly dipped coin and I expect that CAC does this, too. I don't have much experience with dipped coinage since I don't dip coins and I generally avoid pieces that I think were previously dipped, which leaves me less well equipped to answer this question.